“Start up” launching two instances of same programYes, by adding it to the startup folder, it should launch when you log in. What may be an idea, is to uncheck the entries in 'msconfig' for the application, add the application to the startup folder, but also check in the preferences of the application whether it is set to launch on login, or something similar. Would you be able to tell me what the problem application is?

How do I clean dust from a computer?@Aidan - Well, it could be the case that the canned air makes the fan spin more than its designed rpm, plus by actually keeping the blades stationary you blow the dust off more effectively...